He missed a train home after visiting his family in Glasgow on the anniversary of his mother’s death.

But as grumps and ducks into the tiny club called King Tut’s Wah Wah Hut instead, we get the tiniest glimpse of the night’s musical bill. Scrawled at the bottom of the chalkboard is an afterthought, perhaps even chalked on by the “cheeky” unknown band themselves — “Oasis.” That fateful night, our narrator assures us, “changed history.”

“Creation Stories” is a drugs, not-really-sex and Jesus and Mary Chain/Oasis history seen through the eyes of and heard through the c-word-cluttered Glaswegian accent of Ewen Bremner as record impresario and “stupid ginger gargoyle” Alan McGee.

Every movie about any British musical phenomenon of the post-Beatles era is, in its way, an inferior copy of “24 Hour Party People.” “Creation Stories” even covers some of that same ground, with our hero (Leo Flanagan plays him as a teen) remembering the night he and his Bowie/Thin Lizzy-obsessed mates saw The Sex Pistols on British TV and decided that was who they wanted to be,

But this muddy, murky dramedy — starring a “Trainspotting” alumnus, giving us the barest glimpses of this or that Red Letter Date Brit Musical Moment and burdened with occasionally indecipherable accents — is a winner.

“Creation Stories” takes its title from McGee’s memoir, which was named for the groundbreaking record label he founded and ran in the ’80s and ’90s It’s a scrambling “seat of the pants” movie that, like McGee, demands that you meet it on his own terms.

The framing device is a long LA interview the drugs-and-ego-tripping McGee gives to an LA reporter (Suki Waterhouse) in the ’90s, a common vehicle for telling tales of a famous person’s life, real or fictional.

McGee grew up in a house with a brutish dad (Richard Jobson) determined to beat the “wearing your sister’s make-up” out of a son he’s decided will become “a qualified electrician,” like him.

Alan McGee had bigger dreams. We follow him to London and see his first steps into the music scene playing with bands like The Drains and The Laughing Apple.

“I didn’t have any talent, which limited my options some.”

But he did have an ear, and with a team he describes as “accidental alchemists,” they started a club, then record labels, and signing bands like Television Personalities, My Bloody Valentine, The Jesus and Mary Chain, Primal Scream and finally Oasis made their names, allowing this always-broke loan-shark-financed label to leave its mark.

A running gag — every band McGee hypes, from his earliest days to Oasis, is “going to be BIGGER than U-2!”

This Nick Moran film skips through a lot of those “creation stories,” save for the Oasis one. Magazine covers and even that tonight’s-musical-line-up chalkboard with Oasis on it are on the screen for what seems like split seconds. Only the Oasis rise is give much musical screen time.

What “Creation” does instead is follow McGee down the familiar rabbit hole of drugs (Jason Isaac plays the one dealer-too-many who broke McGee — almost) and into political influence, his role in helping the Labour Party and Tony Blair relabel itself and Britain “Cool Britannia” in the ’90s, and McGee’s enraged cynicism about that.

Unlike most films of this genre, the man is more important than his “movement,” and that’s the focus here. And hey, if your biggest impact was giving the world Oasis, you see the point.

Not all of it works. But giddy moments and goofy touches — former Bond villain Steven Berkoff shows up as “my inspiration,” the ghost of infamous 1930s novelist, occultist, thinker and druggy Alastair Crowley — put “Creation Stories” over.

And Bremner, even when we can’t understand every word coming out of that haggis and whisky-sotted gob, wholly inhabits this self-destructive yet idealistic tyro who so shaped his era that he himself almost became “bigger than U-2.”

Rating: unrated, drugs, profanity galore, a hint of sex

Cast: Ewen Bremner, Suki Waterhouse, Leo Flanagan, Jason Isaac, Seána Kerslake with Steven Berkhoff as Alastair Crowley.

Credits: Directed by Nick Moran, scripted by Dean Cavanagh and Irvine Welsh, based on Alan McGee’s memoir of the same title. An RLJE release.

Running time: 1:45